Alternating-current motor.



V. A. PYNN. ALTEBHATIHG CURRENT MOTOR.

APPLIOATIOI FILED JULY 9, 1909.

Patented June 21, 1910.

3 SHEETS-SHEET 1.

mvmr o/e Valm A. Fynn BY M WITllE88E8:

v. A. rim; ALTEBNATING CURRENT MOTOR.

APPLICATION FILED JULY 9', 1909.

962,335. 1 PatentedJune2Ll9l0.

Fig.2.

INVENTOR WI TNESSE 8 I I m l Valre A. Fynn V. A. FINN.

ALTBBHATING OUBREHT IOTOB. Arrucnrol nun mu 0, 1909.

962,335. I Patented June 21,1910.

3 IiIBBTl-BHBBT a.

WITNESSES: [NYE/ 70R I YBf re A.Fynn 417% VALERIE ALFRED FYNN, OFLONDON, ENGLAND.

ALTERNATING-CURRENT MOTOR.

Specification of Letters Patent.

Patented June 21, 1910.

Application-filed July 9, 1909. Serial No. 506,728.

" pertains to make and use the same, reference being had to theaccompanying drawings, forming part of this specification.

My invention relates to means for starting .and operating single phaseinduction motors in which the induced winding responsible for theoperation of the motor is permanently closed on itself independently ofany commutator. It is known that motors of this type have distinctmechanical advantages and good operating characteristics but aredifiicult to start with a powerful torque and with a small current or inother words with a large torque per ampere.

One object of my invention is to provide such means for starting saidmotors with a large torque per ampere as will not make it necessary todimension or dispose the secondary working winding permanently closed onitself with any other objects in view but those of highest effectivenessand efliciency under normal running conditions.

Qther objects of my invention are to avoid the use oi all automaticshort-circuiting devices inside the rotor and to generally improve theircharacteristic properties both at starting and under normal workingconditions.

I achieve my objectloy dividing the rotor laminations int-o two'groupsproviding the rotor with a permanently short-circuited winding extendingover both groups of rotor laminations and a commuted winding alsoextending over both groups of rotor laminations and by so disposingthese two windings relatively the one to the other that their conductorswhich lie adjacent to each other on one group of the rotor laminationsshall be displaced from each other'on the other group of the rotorlaminations. I preferably make this displacement equal to 360/11,degrees. Owing to this disposition it will be impossible for thesewindings to produce inductive efiects the one on the other. Analternating current flowing in one of the windings will not induce aresultant E. M. F. or cause a current to flow in the other winding. Aiiux' which threads the whole of one winding in the same direction willthread equal parts of the other winding in opposite directions and willthus only be able to interact with the former. I make use of thecommuted winding in order to start the motor as an induction or aconduction motor and I make use of the short-circuited rotor winding innormal operation to carry the whole or the greater part of the workingcurrent. I bring this short-circuited winding into play by suitablymodifying the c0nnections of the stator windings either automatically orby hand and after a sufiicient speed has been reached or I induce acurrent in said winding at starting.

In describing some ways of carrying my invention into practice I willrefer to the accompanying diagrammatic drawings of two-pole motorswhere- Figure 1 shows a motor adapted to start mainly as a neutralizedseries conduction motor. Fig. 2 indicates the manner in which conductorswhich are adjacent on one group of rotor laminations are displaced onthe other group. Fig. 3 shows another way of displacing on one group oflaminations, conductors which are adjacent on the other group. Fig. 4illustrates a motor adapted to start as a self-excited series inductionmotor. Fig. 5 indicates the mechanical disposition of the motor partsfor the machine shown in Fig. i.

Fig. 1 shows the preferred form of my motor. This machine comprises twolongitudinally displaced groups of laminations. The permanentlyshort-circuited working winding embracing both groups of rotorlaminations is shown for the sake of clear ness and ease of illustrationas consisting of two permanently interconnected windings 24, 25. Theseare interconnected at four points, 2-8, 29; 26, 27; 32, 33; and 30, 81;they can be interconnected at any number of points, the more the better.The two windings 24, 25 are equivalent to a single winding Wound throughboth groups of rotor laminations. The rotor also carries a commutedwinding disposed on both groups of rotor laminations, and this windingis also shown for the sake of clearness and ease of illustration asconsisting of two interconnected windings 34E, Only "four points areshown as being interconnected; in practice it would be necessary tointerconnect many more points, in fact every coil of 34 and 35 should beinterconnected. The

fact that adjacently situated elements of 8% and 24 on one group oflaminations must be displaced by about 360/n degrees on the other groupof laminations is diagrammatically indicated in Fig. l by connectingpoint 56 to point 61 instead of 57 point 58 to point 63 instead of 59;point to 57 instead of 61 and point 62 to 59 instead of (53. The s'tatoris provided with two groups of lam'inations and carries a main winding9} embracing both groups of laminations. Owing to the above describedrelative position of the short-circuited and the commuted rotor windingsit is only the shortcircuited winding which can be respon to inductiveeffects due to iii', The stator also carries two auxiliary windings 99,66 and 98, 67 on each' group of iaminaticns, the auxiliary windin s oneach group being displaced by 180/n degrees with respect to each otherand one of them being displaced by that angle with respect to 97.Brushes are disposed on the commuted winding 84c, along an axisdisplaced by about 180m degrees with respect to the axis of 97. Thestator windings are arranged in two parallel circuits both fed from themains 1, 2 through the transformer having a primary 3 and a secondary 4.One circuit comprises the winding 97 and the switch 100 and the E. M. F.impressed on this circuit can be adjusted at 5. In the other circuit areconnected in series all the four auxiliary windings and the commutedwinding 34;, 35. The E. M. F. impressed on that circuit can be adjustedat 6 and the circuit is controlled by switch 71, whereas switch 74;allows of the current being simultaneously reversed through 66 and 67.At starting switch 71 is closed and switch 100 is open. Windings 99 and98 are neutralizing windings and so connected as to oppose the ampereturns of the commuted winding; for this reason they inagnetize in thesame direction with reference to the commuted winding. l Vindings 99 andhave no effect on the short-sir cuited winding for they magnetize inopposite directions with reference to the latter. The windings (56, 6'?do duty as lieid windings. They magnetize in the same direction withreference to the commuted Winding so that the ampere turns of thecommuted winding situated on one group of rotor laminations may produceatorque in the same direction as the ampere turns of that same windingdisposed on the other group. VVindings 66, 67 magnetize in oppositsdirections with reference to the short circuited rotor working Windingand it is seen that the machine can be started wi h a powerful torquewithout any current fiowing in the short-circuited winding. To reversethe direction of rotation it is only necessary to reverse the motorfield relatively to the armature current. This ca 1 be When the n anttldCill .ihute to the torque after a s icient l sen reached; Innoroperation short-circuited rotor litre the secondaryof a seliexeitedshunt induction motor.

In Fig. 2 is shown a commuted lap winding 8 35 connected to a commutator48, this winding being placed the correct relative position to theshort-circui worlo ing winding 24:, 25 which is hershown as of thesquirrel-cage type. The arrangement shown in Big. 2 co. sends to thatindicated in Fig. l with this diii'erence h z -Jcv'er that in Fig. it isthe commuted id not the short-sire .ed winding which is wound straightthrough the two groups of rotor laminaticns 4:7. On group 4&6 theconductor 80 of s con'nnuted winding adjacent to the conductor 81 of thesquirrelcage whereas 0: group e? these two con-- ductors are c" racedfrom each other by about SGO/n de rees, it being supposed that each coilof the commuted winning spans "oxiinately a pole pitch.

' the conductor 82 of the com-- muted Wi ing is adjacent to conductor 83of the squirrel-cage in group 4:7 and these same conductors aredisplaced by about 360/41 degrees on oop but neither of the windir, Md.straight through, the conductors or one are (l1SPlit("' about 180/adegree. in. one direction they leave one group of laminations where 101windings illusa gr aininatically reproy of iaminations can achiet. b notwinifling stator winding straight through h other group or by making useoi? .L L separate main winding for ach group A 0 Li [I ()1 animation anddisplacing these two main windings .land 8 by 180/n degrees as shown inFig, Inl ig. 4 these two winding are connected. in series, but they canof course just as well be connected in parallel. The commuted winding isshort-circuited along an axis displacedfrom either of the the .mainfluxes due to 7 and 8 and since 7 and 8 are connected at starting asindicated in Fig. 41 then they will not induce any currents in 2d, .25but will induce currents in 34-, 85 and the machine will start as aself-excited series, induction motor. Then a sufficient speed has beenreached the current through 8 is reversed at 53 thus putting winding 84,out of commission and bringing winding 24:, 25 into play.

In Fig. 5 I have illustrated a possible mechanical disposition of theactive parts constituting the motor which has been more particularlydescribed in connection with ig; 4. The rotor windings are shown insection at 64 and 65 to indicate that they both cross the space between46 and 4-7 diagonally as better shown in Fig. 3.

Having fully described my invention what I claim as new and desire tosecure by Letters Patent of the United States, is:

1. In an alternating current motor, the combination with a stator, of arotor having two longitudinally displaced groups of laminations andprovided with a short-circuited winding and a commuted winding, theconductors of these two windings which lie adjacent to each other on onegroup of rotor laminations being displaced from each other on the othergroup of rotor laminations.

2. In an alternating current motor, the combination with a stator, of arotor provided with a permanently shor -circuited winding and a commutedwinding, the conductors or" these two windings which lie adjacent toeach other on one half of the rotor laminations being displaced fromeach other on the other half.

3. In an alternating current motor, the combination with a statorprovided with a plurality of windings, of a rotor provided with apermanently short-circuited winding and a commuted winding, theconductors of these two windings which lie adjacent to each other on onehalf of the rotor laminations being displaced from each other on theother half.

4. In an alternating current motor, the

combination with a stator provided with a plurality of windings, of arotor provided with a permanently short-circuited winding and a commutedwinding, the conductors of these two windings which lie adjacent to eachother on one half of the rotor laminations being displaced from eachother by 360/ 11, degrees on the other half.

5. In an alternating current motor, the combination with a stator, of arotor having laminations and provided with a short-circui'ted windingand a commuted winding, the conductors of these two wlndmgs which lieadjacen" to each other on one group of rotor laminations being displacedfrom each other on the other group of rotor laminations, and means forpermitting a working current to flow in the commuted winding atstarting.

6. In an alternating current motor, the combination with a stator, of arotor having two longitudinally displaced groups of laminations andprovided with a short-circuited winding and a commuted winding, theconductors of these two windings which lie adjacent to each other on onegroup of rotor laminations being displaced from each other on the othergroup of rotor laminations, means for producing a transformer flux andbrushes on the commuted winding gilisplaced from the axis of thetransformer .9. an.

7. In an alternating current motor, a stator containing two,longitudinally displaced groups of laminations, means for producing amain flux through each group of laminations, a rotor having twolongitudinally diplaced groupsof laminations and rovided with ashort-circuited winding an a commuted winding-the conductors of thesetwo windings which lie adjacent to each other on one group of rotorlaminations being displaced from each other on the other group of rotorlaminations.

8. In an alternating current motor, a stator containing twolongitudinally displaced groups of laminations, means for producing amain flux through each group of laminations, a rotor having twolongitudinally displaced groups of laminations'and provided with ashort-circuited winding and a commuted winding, the conductors of thesetwo windings which lie adjacent to each other on one group of rotorlaminations being displaced from each other on the other group of rotorlaminations, and means for directing the flow of current in the commutedwinding.

9. In an alternating current motor, a stator containing twolongitudinally displaced groups of laminations, means for producing amain flux through each group of laminations the main flux in the onegroup being displaced from the main flux in the other group by ISO/ndegrees, a rotor having two longitudinally displaced groups oflaminations and provided with a shortcircuited winding and a commutedwinding, the conductors of these two windings which lie adjacent to eachother on one group of rotor laminations being displaced from each otheron the other group of rotor laminations, and means for directing theflow of current in the commuted winding.

l 10. In an alternating current motor a stator containing twolongitudinally isplaced groups of laminations, each group being providedwith a main winding and the two main windings being displaced by 180/11,degrees from each other, a rotor having two longitudinally displacedgroups of laminations and provlde'd with a short-circuited Winding and acommuted winding, the conductors of these two windings which lieadjacent to each other on one group of rotor laminations being displacedfrom each I other on the other group of rotor laminations, means for.shortrcircuiting the commuted winding along a stationary axis, andmeans for reversing current through one of the stator windings.

In testimony whereof I have hereunto set m hand and aifixed my seal inthe presence 0 the two subscribing witnesses.

VALERE ALFRED 1mm. [1.. 8.]

\Vit-nesses:

ELIZABETH BAi'LEY, E. E. HUFFMAN.

